So of course I have tried every trick posted to save battery. I have swapped out the phone a couple of times and here is my conclusion: the battery life sucks which is a shame because it contradicts the while point of WP and its live tiles. Here is what I do know:

1. If the phone sits idle with every possible thing off I get about 8-10hrs

2. If I use the phone in any moderate way (some twitter, texting, check FB, things like that) I'm lucky to get 4-5 hrs

3. If I USE the phone (some games, new app installs, etc) forget it I might as well not bother

So basically to use the phone, live apps off, location services off and do nothing interesting with it

Seems as if you got a dud. Good battery life here. I actually ran mine to empty last night. Lasted from about 3pm to 1130pm with a little over moderate use on purpose. Alot of surfing and videos, streaming music on iheart radio, taking videos of my daughter, shot about 30 pics of my dogs and kid. I did alot in 8hours. So imagine if I'm not doing so much? On average I get about 15 hours. Not great, but better than normal. Better than any android. Better than my 920 that is collecting dust.
Sent from my PM23300 using Board Express

Modern batteries don't get better with time. The 8X has the worst battery I have experienced in some time. My observations are that my Lumia 900 gives me about double the life, my RAZR i (yes, an Android phone) gives me over 3 times as much life.

The modern chipset in the 8X should be capable of idling with almost no battery drain for many hours. Indeed, it does so in the tens of Android phones that use the same hardware. I very much doubt a hardware issue here, it feels more like software though it is worth noting that the screen on the 8X is probably a complete battery hog just like the very similar screen on the One X.

To offer some comparisons, my 8X from full charge at 8am one morning will be dead by about 10pm on a typical day. My Lumia 900 will last until about 6pm the following day - another full work day. My RAZR i will last at least two full days and will head into the third with a good 20% battery left. I have very similar setups on each of these devices and I have switched off NFC on all that have it.

Maybe it was just snake oil but I found turning the phone off and back on from when I first unboxed it made a big difference. I was getting terrible battery life as well. I did a test a few nights ago and fully charged it and after about 10 hours of just sitting it was down to 40%. Restarted the phone and did the same test the next night and only dropped to 85%. Same config. I do have NFC disabled but always have.

I've also noticed at full charge it never says 100%...just 99. The battery blows big time. Unsure of what I'm going to do other than swap it for an 810 since I can buy extra batteries :/
Sent from my Windows Phone 8X by HTC using Board Express

I've also noticed at full charge it never says 100%...just 99. The battery blows big time. Unsure of what I'm going to do other than swap it for an 810 since I can buy extra batteries :/
Sent from my Windows Phone 8X by HTC using Board Express

That's such a bummer about your phone man. Again, I think it's device-specific. MAJORITY of people have been reporting great battery life. I haven't turned off LTE since I got my 8x, and the only real "battery saver" I've done is turn off NFC and location until needed.

I get a full day (and then some) out of this. MUCH better than my 4S prior, and on par with a majority of phones I've had (and I've had a lot!) I consider it fantastic considering the live tiles and updates!

I've also noticed at full charge it never says 100%...just 99. The battery blows big time. Unsure of what I'm going to do other than swap it for an 810 since I can buy extra batteries :/
Sent from my Windows Phone 8X by HTC using Board Express

So far so good with my battery. I am coming from the HTC Thunderbolt which could barely make it 6hrs with moderate use. Because of this I got into the habit of keeping chargers at home, work and in the car so that it was always being charged. I've not had to do that with the 8X and I'm able to get 12hrs of use easy. My battery does charge to 100% and I have switched off NFC.

Same with mine! It only says 99% never goes to 100...and to be honest I haven't been impressed with battery life either. I'll see how it does today...on wifi most of the day with moderate use from 7 30 AM to 6 PM. I'm at 88% as of 8 21 AM! Gahhh...

It certainly sounds like you've had bad unit luck. I can attest that the 8X battery does get better over time. I plug mine in to charge every night between 10:00 and 11:30 PM, and take it off the charger at 5:00 AM the next morning. The first night I owned it, I plugged it in with somewhere between 10 and 20% charge (closer to 10% than 20%) and the battery saver had been activated. The next night, it was in the 20%s, and each night after that it's been in the 30%s. As far as usage is concerned, I'm a fairly heavy texter and emailer (I'm in IT and my corporate Exchange account syncs on my 8X; our help desk software creates a LOT of emails). The calendar also syncs with my Exchange server, and I use the Facebook and NextGen Reader apps moderately. I use OneNote for note taking a bit (largely using voice commands) and I take a few pictures here and there. So I'm not a "light user".

Return it if you already have been using for a few days. The battery life does improve with time. Seem like you have a defective unit.

Idling, mine consumed this past Sunday about 15% in a 12 hr period. I think it's fine. I haven been getting 12 hr with moderate use (but poor signal coverage, which drains batteries faster) and it's been improving daily since I got it last week.

It's not the best battery on the market, but I get 12 hours pretty easily with normal use on 4G, wifi is on, plenty of live tiles, NFC is off, getting some push notifications for twitter, a few games. Run all day from 7am to 7pm, still have 20% or so left.

I charged my phone overnight. Stopped chaging about 10am.
I have sent the usual texts,20+ mins on Wordfeud, 20 mins playing Peekaboo with my nephew, half a dozen photos, some time on people hub.
Its currently at Ł2% and states 6 hours left.
If I dont use it much it will last me to the morning.